Arthur w



A. W. ROBINSON.

' DIPPER DREDGE.

APPLICATION FILED MAR. 31.1919.

1,323,323. Patented Dec. 2,1919.

UNITED STATES PATENT OFFICE.

ARTHUR W. ROBINSON, OI MONTREAL-TQU EBEG, CANADA.

nIrrnn-nnnnsn To all whom it may concern: 1

Be it known that I ARTHUR W.ROBIN- I bominion of Canada, 'and a resident of the city of Montreal,

son, a citizen of the Province of Quebec, Dominion of Canada, have invented certain new and useful Improvements in Dipper-Dredges, of which the following is a specification, reference'being' had to the accompanying drawings.

This invention pertains to that class of dredge in which a single dipper is employed mounted on the end of a rigid dipper arm,

feeding it in or out so as to alter the radius of the dipper arc, tothe construction and arrangement of'the sheaves for guiding the hoisting and other ropes which affect the movements of the dipper, and finally to an improved arrangement of the backing. line which draws the dipper rearwardly.

This invention is a further development of and improvement upon that set forth in my United States Letters Patent No. 1,081,-

774 dated December 16, 1913, in which a somewhat similar arrangement-0f certain of the arts is shown; but in my present invention the arrangement of the sheaves, the

manner of controlling the feeding of the dipper arm and the arra ement and manipulation of the backing line are all essentially different, from which difierences flowa series'of advantages which will be referred to below.

Referring to the drawings, Figure 1 1s a side elevation of the parts as assembled and mounted on the front end '1 of. a dredge seow; Fig. 2 is a plan view. of the boom,

showing the constructioniand arrangement of the sheaves, ropes and dipper arm sup port; Fig. 3*is an end view. of the lower sheaves located in the scowj'Fig. 4 a view of the forward end of the scow correspond ing to Fi 1, but with the boom turned at.

right ang es, thus showing the twist of the hoisting ropes; Fi 5 is an elevation, somewhat enlarged, of t e support'for the dipper arm upon the boom.

In the'drawings 1 represents the scow, 2 the boom or swinging member, 3 the top stay by which the boom may be supported from the usual frame 4, which is supported by back stay 5. 6 is the dipper arm, 7 the dipper, 8, 8, double hoisting ropes, which pass Specification of Letters Patent.

shown.

from the dipper 7 over two sheaves 10, 10, spaced apart as shown and suitably supported at the forward end of the boom,

thence over two sheaves 9, 9, suitably mounted near the lower end of the ,boom

and separated by a distance sufficient to- -The roller acts as the support on the boom for the dipper arm and the movements of the dipper arm are effected and controlled by wire ropes which are received within a circumferential recess 15 in the center of Patented Dec. 2, 1919. Application filed March 81,1919. Serial No. 286,898. I

the roller 13, so that it also acts as a sheave f for these ropes, one of which 16, passes over this roller and is attached atone end to the lower part of the dipper arm, as shown, while the other one, 17, passes under the roller and is attached to the upper end of the dipper arm, as shown. The opposite ends of both ropes are attached to a drum l8 mounted on the lower part of the boom and which is actuated by a suitable motor 19,

pinion 20 and gear 21. The dipper arm is retained in place on the roller 13 by a saddle block 22, which incloses it and through which it freelyslides when actuated and. controlled by the ropes 16 and-17. The

drum 18 is provided with the usual friction brake, not shown, to control the too free downward movement of the dipper arm and through the instrumentality of the steam or other motor 19' and its associated, gearing,

the dipper arm will be moved in or out by power. This is of special advantage in con trolling the position of the dipper both tion for dumping. '23 is the backing'line,.'so called, necessary or useful in this type of dredge to pull the dipper to working posi-- tion. It is connected as at 24 to the dipper.

supported in the hull between the sheaves 11, see Fig. 3, and thence to the hoisting maehmery in the usual way.

. It will be noted that although Iemploy in this invention here and there a known feature or element, yet that some of them are .while dredging and while getting into posithe hoist for which is on one The feed of the dipper arm has in many instances heretofore been controlled by rack and pinion with friction brake, which are liable to disorganization because of wear and breakage due to the great weight of the dipper arm and its load resting on the pinion and also because of the excessive strains to which it is subjected in use. These objections are avoided by the employment under my invention of a smooth solid roller as the support for the dipper arm. The movement of the arm is controlled by wire ropes located within and protected by a recess in the center of the roller. It thus acts as a reliable and durable support for the dip? per arm, there being extended contacting surfaces between them, and also as a sheave for the ropes. The wire ropes provide a powerful and flexible control and the drum and gear to which they are attached are situated on or near the base of the boom near the center of motion where their momentum, due to swinging, is less, in fact, being to the rear of the center, they act more or less as a counterbalance for the boom, instead of injuriously loading it near the middle, as when rack and pinion attachments were used; and, as stated, the employment'of a motor to control and actuate the feed of the dipper armgreatly facilitates its operation. The spreading of the main hoisting ropes in the manner described not only provides for a solid dipper arm between them but enables me to employ a centrally located backing line, which is carried out to the dipper arm on the axis of rotation of the turn table. The fairlead, through which it passes, is always fair because it is'attached to and moves with the base of the boom, thus avoidf ing the objectionable features in fairleads as heretofore used, due to the bend in the backing line occasioned by the degree to which the boom is swung, which, on many occasions, was so sharp as to injure the line. In

some instances also where the fairlead hasbeen placed in the hull, if rough water was encountered, it has been admitted through the fairlead opening, necessitating pumping, or other operation forits removal. In. addition to this also, instead of having the sheaves 9, 9, on the boom inclined to each other, as in my former patent, I now make them parallel and correspondingly spread or the defective operation of amasses the lower sheaves 11, 11, thus not only roviding for the backing line, but also ma in a better and simpler construction at reduce cost. It will be noted that the hoisting ropes between the sheaves 9 and 11 pass vertically in substantially the axisof rotation of the turntable. Thus they twist on one another to a slight extent during the swinging of the boom and are not always in the plane of the sheaves; but it is found in practice that a slight deviation is quite permissible and the very small angle is taken care of by the flanges forming the grooves of theseveral sheaves.

I wish it to be understood that the description and drawingshereof disclose one form only of dredge mechanism in which my invention may be embodied, because those familiar with such matters will at once understand that my improvements, .wholly or in part, may be embodied in mechanism quite widely different fromthat which I have described and illustrated. For instance, the dipper hoistingropes are shown as a pair of single ropes separated by a space sufficient to permit the dipper arm to operate between them, but, as is well known, each member of the pair may consist of more than one rope. This is desirable in heavy work because a numbenof small ropes, while equaling the strength of a single large one, will have greater flexibility and therefore require less power. The peripheries of the guide sheaves will, of course, .be made to correspond to the. special construction of hoisting ropes. When in the claims I refer to duplex hoisting ropes, I mean that there shall be a pair separated as stated in the specification, irrespective of the number of individual ropes comprised in each member of the pair. Also, valthough I prefer that the winding drum for the ropes 16 and 17, which control the dipper arm, and the motor therefor, if one be used, shall be at the base of the boom and in rear of the axis of the turntable, since, as stated, certain important advantages result from that construction and arrangement, yet, if preferred, these parts may be located wherever they will e ciently perform their functions. It will therefore be obvious to those who are familiar with such matters that modifications may be made in the details of construction of the parts described and illustrated without departing from the essentials of the invention. I therefore do not limit myself to such details.

I claim:

1. In a dipper dredge, embodying among other things the usual A frame or mast, and a swinging boom, a dipper arm supported thereby, a combined sheave and roller sup-, ported on the boom with which the dipper arm engages, a single winding drum, ropes attached respectively at one of their ends to the upper and lowerparts of the dipper arm and passin respectively under and over the combined s eave and roller and attached at their other ends to the winding drum in such manner that its rotations will wind and unwind them respectively, and means to control the rotations of the drum.

2. In a'dipper dredge embodying among other things the usual A frame or mast and a swinging boom, a dipper arm su ported thereby, a combined sheave and rol er supported on the boom and a supporting the dipper arm, a single winding drum, ropes attached respectively at one of their ends to the upperand lower parts of the dipper arm and passing respectively under and over the combined sheave and roller and attached at their other ends to the winding drum in such manner that its rotation will wind and winding drum supported upon the $5 roller and attached at their other ends to the winding drum in such manner that its unwind them respectively and means to control the rotations ofthe drum.

3. In a dipper dredge embodying among other things t e usualA 'frame or mast and a swinging boom, a dipper arm supported thereby, a combined sheave and roller supported on the boom with which the dipper arm engages, a single winding drum, ropes attached respectively at one of their ends to the upper and lower parts of the dipper arm and passing respectively under and over the combined sheave and roller and attached at their other ends to the winding drum in suchmanner that its rotation will the upper and lower parts of the dipper arm and passing respectively under and over the rotations will wind and unwind them respectively, and means to control the rotations of the drum.

5. In a dipper dredge, a turn table, a

swinging boom supported on the turn table,

a solid dipper arm supported by the boom,

a combined sheave and roller supported on the boom, a winding drum and a motor supported upon theturn table in rear of its axis of rotation, ropes attached respectively at one of their ends to the upper and lower parts of the dipper arm and passin respectively under and over the combine sheave and roller and attached at their other ends to the windin drum in such manner as to he wound an unwound respectively by its rotations, and means whereby the motor controls the rotations of the 6. In a dipper dredge a swinging boom, a dipper arm supported by the boom, a com bined sheave and roller supported on the boom and supporting and guiding the dipper arm and having a centrally located circumferential recess and a smooth cylindrical surface at each side of the recess, a winding drum, ropes attached to the dipper arm and extending respectively under and over said combined sheave and roller within the recess therein and then to opposite sides of'the Winding drum so that its r0- tations will wind and unwind'the ropes respectively, and means to control the rotations of the drum.

7. In a dipper dredge a swinging boom, a roller supported on the boom, 21

solid dipper arm supported by the combined sheave and roller, duplex hoisting ropes supported and guided by parallel sheaves arranged-iii pairs and separated by a distance at least equal to the width of the dipper arm, a windin drum,

means on the dredge to guide said oisting ropes to the winding drum, another winding drum, ropes attached respectively at one of their ends to the. upper and lower parts of the dipper arm and passing respectively under and over said combm'ed sheave and roller and attached'at their other ends to the last named windin drum, and means to control the rotation o the last named "winding drum.

8. Ina dipper e a swinging boom,

a combined sheave an roller supported on the boom, a-solid dipper arm supported by the. roller, duplex hoistingropes supported and guided by parallel sheaves arranged in pairs and separated by a distance at least equal to the width of the dipper arm, a winding drum, means on the dredge to guide said hoisting ropes to the, windingdrum, another winding drum, ropes attached respectively at one of their ends to the up per and lower parts of the dipper arm and passing respectively under and over. said roller and attached at their other ends to the last named combined sheave and winding drum, and a motor adapted to positively rotate said last named drum.

9. In adipper dredge a swinging boom, a combined sheave and roller supported on the boom, a solid dipper arm supported by the roller, duplex hoisting ropes supported and guided by parallel sheaves arranged in pairs and separated by a distance at least equal, to the width of the dipper arm, a winding drum, means on the dredge to guide said hoisting ropes to the winding drum, another winding drum, ropes attached respectively at oneof their ends to the upper and lower parts of the dipper arm and passing respectively under and over said combined sheave and roller and attached at their other ends to the last named winding drum, and a motor adapted to positively rotate said last named drum, the said drum and the motor being in rear of the axis of rotation of the boom.

10. In a dipper dredge a turn table, a swinging boom supported on the turn table, a roller supported on the boom, a dip er arm supported by the roller, duplex l i oisting ropes supported and guided by parallel sheaves arranged in pairs and separated by a distance at least equal to the width of the dipper arm, a Winding drum, means on the dredge to guide said hoisting ropes to the winding drum, another winding drum, ropes attached respectively at one of their ends to the upper and lower parts of the dipper arm and passing respectively under and over said roller and attached at their other ends to the last named winding drum, means to control the rotation of the last named Winding drum and a backing line having a guide sheave on the scow the forward arc whereof is in the axial line of rotation of the turn table, another guide sheave on the boom the rearward arc whereof is substantially in, the axial line of rotation of the turn table and a fairlead on the turn table, the backing line being attached to the winding drum at one end, passing under and over the said guide sheaves respectively, through the fairlead," and thence to the dipperv arm. 4

In testimony whereof I have signed my name to this specification.

ARTHUR W. ROBINSON. 

